* only incompletely written out before a crash, which should only happen for
* log records that were not considered committed). */
-// Rough size limit for a log segment. This is not a firm limit and there are
-// no absolute guarantees on the size of a log segment.
-#define LOG_SEGMENT_SIZE (1 << 22)
-
#define HEADER_MAGIC 0x676f4c0a
#define FOOTER_MAGIC 0x2e435243
+static size_t readbuf(int fd, char *buf, size_t len)
+{
+ size_t total_bytes = 0;
+ while (len > 0) {
+ ssize_t bytes = read(fd, buf, len);
+ if (bytes < 0 && errno == EINTR)
+ continue;
+ g_assert(bytes >= 0);
+ if (bytes == 0)
+ break;
+ buf += bytes;
+ len -= bytes;
+ }
+ return total_bytes;
+}
+
static void writebuf(int fd, const char *buf, size_t len)
{
while (len > 0) {
return;
fdatasync(log->fd);
+
+ /* Update disk-space usage statistics for the journal file. */
+ g_atomic_int_add(&log->disk_used, -log->current_log->disk_used);
+ struct stat statbuf;
+ if (fstat(log->fd, &statbuf) >= 0) {
+ /* Convert from 512-byte blocks to 1-kB units */
+ log->current_log->disk_used = (statbuf.st_blocks + 1) / 2;
+ }
+ g_atomic_int_add(&log->disk_used, log->current_log->disk_used);
+
while (log->committed != NULL) {
BlueSkyCloudLog *item = (BlueSkyCloudLog *)log->committed->data;
g_mutex_lock(item->lock);
/* A stale reference to a journal file which doesn't exist any longer
* because it was reclaimed. Return NULL. */
} else if (map == NULL) {
- g_print("Adding cache file %s\n", logname);
+ if (bluesky_verbose)
+ g_print("Adding cache file %s\n", logname);
map = g_new0(BlueSkyCacheFile, 1);
map->fs = fs;
g_mutex_lock(map->lock);
map->cond = g_cond_new();
map->filename = g_strdup(logname);
+ map->log_dir = clouddir;
map->log_seq = log_seq;
map->log = log;
g_atomic_int_set(&map->mapcount, 0);
ftruncate(fd, 5 << 20); // FIXME
close(fd);
}
-
- // If the log file is stored in the cloud, we may need to fetch it
- if (clouddir >= 0 && start_fetch)
- cloudlog_fetch_start(map);
} else {
g_mutex_lock(map->lock);
}
+
+ /* If the log file is stored in the cloud and has not been fully fetched,
+ * we may need to initiate a fetch now. */
+ if (clouddir >= 0 && start_fetch && !map->complete && !map->fetching)
+ cloudlog_fetch_start(map);
+
g_mutex_unlock(log->mmap_lock);
if (map != NULL)
g_atomic_int_inc(&map->refcount);
size_t offset, size_t length)
{
g_atomic_int_inc(&cachefile->refcount);
- g_print("Starting fetch of %s from cloud\n", cachefile->filename);
+ if (bluesky_verbose)
+ g_print("Starting partial fetch of %s from cloud (%zd + %zd)\n",
+ cachefile->filename, offset, length);
BlueSkyStoreAsync *async = bluesky_store_async_new(cachefile->fs->store);
async->op = STORE_OP_GET;
async->key = g_strdup(cachefile->filename);
async->start = offset;
async->len = length;
+ async->profile = bluesky_profile_get();
bluesky_store_async_add_notifier(async,
(GFunc)cloudlog_partial_fetch_complete,
cachefile);
static void cloudlog_partial_fetch_complete(BlueSkyStoreAsync *async,
BlueSkyCacheFile *cachefile)
{
- g_print("Partial fetch of %s from cloud complete, status = %d\n",
- async->key, async->result);
+ if (bluesky_verbose || async->result != 0)
+ g_print("Fetch of %s from cloud complete, status = %d\n",
+ async->key, async->result);
g_mutex_lock(cachefile->lock);
if (async->result >= 0) {
+ if (async->len == 0) {
+ if (bluesky_verbose)
+ g_print("Complete object was fetched.\n");
+ cachefile->complete = TRUE;
+ }
+
/* Descrypt items fetched and write valid items out to the local log,
* but only if they do not overlap existing objects. This will protect
* against an attack by the cloud provider where one valid object is
BlueSkyRangeset *items = bluesky_rangeset_new();
int fd = openat(cachefile->log->dirfd, cachefile->filename, O_WRONLY);
if (fd >= 0) {
+ gboolean allow_unauth;
async->data = bluesky_string_dup(async->data);
+ allow_unauth = cachefile->log_dir == BLUESKY_CLOUD_DIR_CLEANER;
bluesky_cloudlog_decrypt(async->data->data, async->data->len,
- cachefile->fs->keys, items);
+ cachefile->fs->keys, items, allow_unauth);
uint64_t item_offset = 0;
while (TRUE) {
const BlueSkyRangesetItem *item;
item = bluesky_rangeset_lookup_next(items, item_offset);
if (item == NULL)
break;
- g_print(" item offset from range request: %d\n",
- (int)(item->start + async->start));
+ if (bluesky_verbose) {
+ g_print(" item offset from range request: %d\n",
+ (int)(item->start + async->start));
+ }
if (bluesky_rangeset_insert(cachefile->items,
async->start + item->start,
item->length, item->data))
g_warning("Unable to open and write to cache file %s: %m",
cachefile->filename);
}
+
+ bluesky_rangeset_free(items);
} else {
- g_print("Error fetching from cloud, retrying...\n");
+ g_print("Error fetching %s from cloud, retrying...\n", async->key);
cloudlog_partial_fetch_start(cachefile, async->start, async->len);
}
+ /* Update disk-space usage statistics, since the writes above may have
+ * consumed more space. */
+ g_atomic_int_add(&cachefile->log->disk_used, -cachefile->disk_used);
+ struct stat statbuf;
+ if (fstatat(cachefile->log->dirfd, cachefile->filename, &statbuf, 0) >= 0) {
+ /* Convert from 512-byte blocks to 1-kB units */
+ cachefile->disk_used = (statbuf.st_blocks + 1) / 2;
+ }
+ g_atomic_int_add(&cachefile->log->disk_used, cachefile->disk_used);
+
bluesky_cachefile_unref(cachefile);
g_cond_broadcast(cachefile->cond);
g_mutex_unlock(cachefile->lock);
{
g_atomic_int_inc(&cachefile->refcount);
cachefile->fetching = TRUE;
- g_print("Starting fetch of %s from cloud\n", cachefile->filename);
+ if (bluesky_verbose)
+ g_print("Starting fetch of %s from cloud\n", cachefile->filename);
BlueSkyStoreAsync *async = bluesky_store_async_new(cachefile->fs->store);
async->op = STORE_OP_GET;
async->key = g_strdup(cachefile->filename);
+ async->profile = bluesky_profile_get();
bluesky_store_async_add_notifier(async,
(GFunc)cloudlog_partial_fetch_complete,
cachefile);
bluesky_store_async_unref(async);
}
+/* Map and return a read-only version of a byte range from a cached file. The
+ * CacheFile object must be locked. */
+BlueSkyRCStr *bluesky_cachefile_map_raw(BlueSkyCacheFile *cachefile,
+ off_t offset, size_t size)
+{
+ cachefile->atime = bluesky_get_current_time();
+
+ /* Easy case: the needed data is already in memory */
+ if (cachefile->addr != NULL && offset + size <= cachefile->len)
+ return bluesky_string_new_from_mmap(cachefile, offset, size);
+
+ int fd = openat(cachefile->log->dirfd, cachefile->filename, O_RDONLY);
+ if (fd < 0) {
+ fprintf(stderr, "Error opening logfile %s: %m\n",
+ cachefile->filename);
+ return NULL;
+ }
+
+ off_t length = lseek(fd, 0, SEEK_END);
+ if (offset + size > length) {
+ close(fd);
+ return NULL;
+ }
+
+ /* File is not mapped in memory. Map the entire file in, then return a
+ * pointer to just the required data. */
+ if (cachefile->addr == NULL) {
+ cachefile->addr = (const char *)mmap(NULL, length, PROT_READ,
+ MAP_SHARED, fd, 0);
+ cachefile->len = length;
+ g_atomic_int_inc(&cachefile->refcount);
+
+ close(fd);
+ return bluesky_string_new_from_mmap(cachefile, offset, size);
+ }
+
+ /* Otherwise, the file was mapped in but doesn't cover the data we need.
+ * This shouldn't happen much, if at all, but if it does just read the data
+ * we need directly from the file. We lose memory-management benefits of
+ * using mmapped data, but otherwise this works. */
+ char *buf = g_malloc(size);
+ size_t actual_size = readbuf(fd, buf, size);
+ close(fd);
+ if (actual_size != size) {
+ g_free(buf);
+ return NULL;
+ } else {
+ return bluesky_string_new(buf, size);
+ }
+}
+
/* The arguments are mostly straightforward. log_dir is -1 for access from the
* journal, and non-negative for access to a cloud log segment. map_data
* should be TRUE for the case that are mapping just the data of an item where
BlueSkyRCStr *bluesky_log_map_object(BlueSkyCloudLog *item, gboolean map_data)
{
BlueSkyFS *fs = item->fs;
- BlueSkyLog *log = fs->log;
BlueSkyCacheFile *map = NULL;
BlueSkyRCStr *str = NULL;
int location = 0;
size_t file_offset = 0, file_size = 0;
- gboolean range_request = TRUE;
+ gboolean range_request = bluesky_options.full_segment_fetches
+ ? FALSE : TRUE;
if (page_size == 0) {
page_size = getpagesize();
file_size = item->location.size;
}
- if (map->addr == NULL) {
- int fd = openat(log->dirfd, map->filename, O_RDONLY);
-
- if (fd < 0) {
- fprintf(stderr, "Error opening logfile %s: %m\n", map->filename);
- goto exit2;
- }
-
- off_t length = lseek(fd, 0, SEEK_END);
- map->addr = (const char *)mmap(NULL, length, PROT_READ, MAP_SHARED,
- fd, 0);
- g_atomic_int_add(&log->disk_used, -(map->len / 1024));
- map->len = length;
- g_atomic_int_add(&log->disk_used, map->len / 1024);
-
- g_atomic_int_inc(&map->refcount);
-
- close(fd);
- }
-
/* Log segments fetched from the cloud might only be partially-fetched.
* Check whether the object we are interested in is available. */
if (location == CLOUDLOG_CLOUD) {
goto exit2;
}
if (rangeitem == NULL) {
- g_print("Item at offset 0x%zx not available, need to fetch.\n",
- file_offset);
- if (range_request)
- cloudlog_partial_fetch_start(map, file_offset, file_size);
+ if (bluesky_verbose) {
+ g_print("Item at offset 0x%zx not available, need to fetch.\n",
+ file_offset);
+ }
+ if (range_request) {
+ uint64_t start = file_offset, length = file_size, end;
+ if (map->prefetches != NULL)
+ bluesky_rangeset_get_extents(map->prefetches,
+ &start, &length);
+ start = MIN(start, file_offset);
+ end = MAX(start + length, file_offset + file_size);
+ length = end - start;
+ cloudlog_partial_fetch_start(map, start, length);
+ if (map->prefetches != NULL) {
+ bluesky_rangeset_free(map->prefetches);
+ map->prefetches = NULL;
+ }
+ }
g_cond_wait(map->cond, map->lock);
} else if (rangeitem->start == file_offset
&& rangeitem->length == file_size) {
- g_print("Item now available.\n");
+ if (bluesky_verbose)
+ g_print("Item %zd now available.\n", file_offset);
break;
}
}
file_size = item->data_size;
}
- str = bluesky_string_new_from_mmap(map, file_offset, file_size);
- map->atime = bluesky_get_current_time();
-
- g_print("Returning item at offset 0x%zx.\n", file_offset);
+ str = bluesky_cachefile_map_raw(map, file_offset, file_size);
exit2:
bluesky_cachefile_unref(map);
if (g_atomic_int_dec_and_test(&mmap->mapcount)) {
g_mutex_lock(mmap->lock);
- if (g_atomic_int_get(&mmap->mapcount) == 0) {
- g_print("Unmapped log segment %d...\n", mmap->log_seq);
+ if (mmap->addr != NULL && g_atomic_int_get(&mmap->mapcount) == 0) {
+ if (bluesky_verbose)
+ g_print("Unmapped log segment %d...\n", mmap->log_seq);
munmap((void *)mmap->addr, mmap->len);
mmap->addr = NULL;
g_atomic_int_add(&mmap->refcount, -1);
}
g_mutex_unlock(mmap->lock);
}
+ g_assert(g_atomic_int_get(&mmap->mapcount) >= 0);
}
/******************************* JOURNAL REPLAY *******************************
projects / bluesky.git / blobdiff